Role of Van Hove singularities and effective mass anisotropy in polarization-resolved high harmonic spectroscopy of silicon Paper

Researchers from the HiLASE Centre and Charles University have published a joint study in the journal of Communications Physics, focusing on the emission of high harmonics by silicon crystal under its irradiation by a few-cycle laser pulse. In this work, the group of Martin Kozak (Charles University) measured the energy of photons emitted during irradiation in the reflection geometry. This enabled to perform a direct comparison with the predictions based on the time-dependent density functional theory (TDDFT) made by Thibault Derrien (HiLASE Centre).

The paper evidences the importance of the carrier-envelope phase and of the crystal’s orientation at material irradiation with ultrashort laser pulses. The study supports an important role of Van Hove singularities in the angular distribution of the emitted harmonics. Overall, this work demonstrates that quantum approaches and supercomputing are essential for the development of modern laser technologies.

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